1. Field of the Invention
The present invention relates to a combination connector constituted by a plurality of connector housings stacked together in a multi-stage manner.
2. Background of the Related Art
FIGS. 5 and 6 show an combination connector 1 disclosed in Unexamined Japanese Patent Publication No. Hei 2-223171. This combination connector 1 comprises three connector housings 2, 3 and 4 and a cover 5 for closing the uppermost connector housing 2. Elastic engaging frame portions 6, each defining a engaging hole 7, project from a lower portion of each of opposite side surfaces of each of the connector housings 2 and 3, and engaging projections 8 are formed on an upper portion of each of the opposite side surfaces. Only engaging projections 8 are formed on the lowermost connector housing 4. Elastic retaining frame portions 6, each defining a engaging hole 7, are formed also on the cover 5 which closes the uppermost connector housing 2.
As shown in FIG. 6, the connector housings 2, 3 and 4 are stacked together in a multi-stage manner, and the engaging projections 8 on the lower one of the adjacent connector housings are fitted and engaged in the engaging holes 7 provided at the upper connector housing, thereby combining the three connector housings 2, 3 and 4 together.
In the above combination connector 1, however, when the connector housings 2, 3 and 4 are to be combined together, each retaining frame portion 6 is much flexed or elastically deformed when it slides over the engaging projection 8, and therefore the retaining frame portions 6 have a permanent set in fatigue because of this excessive flexing. As a result, there is a possibility that the connector housings 2, 3 and 4 are accidentally disconnected from each other. And besides, when the retaining frame portions 6 have a permanent set in fatigue, there is encountered a problem that the connector housings 2, 3 and 4 can shake relative to each other, and therefore can not be firmly combined together.